Submission #1123019

#	Time	Username	Problem	Language	Result	Execution time	Memory
1123019		njoop	Mountains (NOI20_mountains)	C++20	100 / 100	600 ms	26252 KiB

Mountains

#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>
#define int long long
using namespace std;
using namespace __gnu_pbds;

typedef tree<int, null_type, less_equal<int>, rb_tree_tag,
             tree_order_statistics_node_update>
    ordered_multiset;

ordered_multiset s;
int l[300010], r[300010], arr[300010], n, ans;

signed main() {
    cin >> n;
    for(int i=1; i<=n; i++) {
        cin >> arr[i];
        l[i] = s.order_of_key(arr[i]);
        s.insert(arr[i]);
    }
    s.clear();
    for(int i=n; i>=1; i--) {
        r[i] = s.order_of_key(arr[i]);
        s.insert(arr[i]);
    }
    for(int i=1; i<=n; i++) {
        ans += l[i]*r[i];
    }
    cout << ans;
    return 0;
}

• Subtask 1: 2 / 2
• Subtask 2: 4 / 4
• Subtask 3: 9 / 9
• Subtask 4: 36 / 36
• Subtask 5: 28 / 28
• Subtask 6: 9 / 9
• Subtask 7: 12 / 12